An air intake device offers simplified construction, reduced size, lowered cost, etc., while facilitating disposing of throttle body and driving part in intake air passage, allowing throttle body to be reliably held, and eliminating possible occurrence of intake air leakage, etc., thus positively securing the performance. The air intake device includes an actuator and an intake air manifold made of resin. In actuator, there are provided a throttle body, a throttle valve, a motor for opening/closing throttle valve, and a power transmission mechanism. Throttle valve and motor are positioned and held on one side of a support member, and power transmission mechanism is on the other side. In intake air manifold, a housing chamber is provided. When a fixing part of support member is jointed to a part to be fixed of intake air manifold, throttle body and motor are accommodated in a predetermined position in housing chamber.